The invention relates to an ultrasonic probe which can be introduced into a body, for example, into the body of a patient.
An ultrasonic probe of this type is known from the German LP No. 23 05 501. There is a desire to employ such ultrasonic probes in conjunction with endoscopy. In such a case, thus, the ultrasonic probe must be introduced into the body cavity of the patient at least in conjunction with an endoscopic optical insert. The endoscopic optical insert allows the physician to observe the examination location in the interior of the patient's body at which the ultrasonic probe is to be placed from the outside. When a suitable examination location has been found, then the ultrasonic applicator is placed in operation for the purpose of recording cross-sectional images. The type of scanning is as desired; thus, it can be a matter of a pure linear scan or a matter of an electronically generated sector scan. Likewise, a C-scan or the like is possible. An ultrasonic probe which is employed in conjunction with an optics insert in endoscopes is already known per se from the German OS No. 30 09 482. The ultrasonic transducer of this ultrasonic probe is a matter, however, of a mechanically pivoted ultrasonic head for sector scanning. Such a scanning head at most requires a signal line for the excitation and for the echo reception and a line for an angle generator. Apart from the drive wire or the drive shaft for the execution of the pivot motion of the acoustic head and apart from the angle generator, no space is required for further acoutrements of the ultrasonic transducer. For this reason, the ultrasonic transducer can be completely accomodated together with an optical insert in the probe tube which carries the transducer.
Such a structure is not possible without further ado given employment of an ultrasonic array. An ultrasonic array allows a larger-surface scanning of the examination subject, in particular of locations such as lie close to the array. Given a sector scanning, usable images only derive at a certain distance from the tip of the sector line field, i.e. from the acoustic head.
In order to be able to fully exploit the advantage of an ultrasonic array, the array should at least exhibit such a plurality of transducer elements that a usably resolved ultrasonic image with sufficient width is produced. Practice shows that usable images are supplied when the number of transducer elements lies at at least approximately 40 through 50 individual elements. This relatively high number of individual elements which can in turn be sub-divided (for example into two or, preferably, even more such as, for example, eight subtransducers in the manner of the U.S. Pat. No. LP 4,305,014), however, requires a correspondingly high number of signal lines. As a rule, commercially available signal lines are relatively thick (they have a diameter in the range of .phi.=0.6 mm), since, for the purpose of mutual HF noise suppression, they are also provided with a HF protective jacket consisting, for example, of gold-plated copper wire in addition to the normal insulating layer consisting, for example, of Teflon.